You are the only one who can open that particular link, so I can't see what you did or missed on that puzzle.

All the puzzles I have done are possible to complete. You need to work each clue and mark all the negatives in order to determine the positives - i.e. Mark finished some time before the Dodge owner; Mark is not last, the Dodge owner is not first (or anyplace after Mark) Mark does not own the Dodge.

Keep working at them and enjoy yourself, I laugh at myself when I make an obvious mistake, then make it again the next time! So no, I don't think you're thick, consider that you're human and our brains don't always work like computers!

The person who uses Biz is not Samara.
Neither the person who arrived on Friday nor the person who uses Biz is Haley.
The person who arrived on Wednesday doesn't use Ultra.
The five individuals are the person who arrived on Thursday, the bowling star, the person who arrived on Wednesday, the person who uses Downy and Melany.
The person who uses Biz is not the basketball star.
The basketball star arrived the day after the football star.
The person who uses All is not Melany.
The billiards star is not Samara.
Of Payton and the person who arrived on Friday, one is the baseball star and the other is the basketball star.
The person who arrived on Thursday is the basketball star.
The person who uses Ultra arrived the day after the person who uses Downy.

In order to solve this puzzle, we need the other 2 days of the week, the other name of the person, and the other name of the detergent. Since they go in alphabetical order or the order of the days of the week, it probably can't be solved without them. In any case, it would make it easier or doable.